So, a rodent ate my sound insulation...

So here's the story. I'm on a tight budget and but needed a nice car to take clients to houses in. So after much searching I found a 2003 XLS Avalon in Podunk, MI. Wellll...it turns out that apparently it had been parked for a while, and I didn't know about this. Thus about two weeks after I got it the ventilation in the cab started smelling bad when the weather got hotter. Then, it stopped before I did anything definitive. And the cause of the problem got pushed down the to do list. So the car is fine now, though the fan seems a little weak. This is ok until it got really hot here the last week or so. So I finally get around to getting a replacement cabin air filter. Go to change the filter and find that a rodent has made a nest out of the sound proofing insulation on top of the cabin air filter. Talk about a seriously clogged filter! Once cleanup is done, the new filter installed, and everything buttoned back up I start the fan up. The fan is as strong as it should be now, but alas rather noisy Talked to a dealer and was told that they don't sell just the insulation, it's part of the fan assembly which runs ~$1200...not happening! So, any advice on what to do?

Thanks in advance